Relaying arrangement



S. P. sHAcKLEToN ET A1.

RELAYING ARRANGEMENT Filed Nov. 22, 192s Nov. 27, 192s.

Patented Nov. 27, 1928.

UNITED STATES PATEVT orifice.

SAMUEL P. SHACKLETON, OF WYOIYING, AND AROLD A. HANSEN, OF `WEST GRANGE, NEVI JERSEY, ASSIGNORS TO AMERECAN TELEPHONE AND TELEGRAPH COMPANY,

A CURPORATION OF NEW YORK.

antenne Annaivenivinnrr.

Application iled November 22, 1926. Serial No. 150,064.

rlhis invention relates to improved arrangements tor relaying signalingk or ringing currents transmitted over aline, the characteristics of which are such that currents ot this type might need reintorceinent in strength before arrival at their destination.

A. particular illustration, wherein a device ot the invention might be utilized, Vis in a telephone system where it is desired to transmit low frequency signaling current, such vas 2U- eycle current, from a composite ringer at a central oiilce to a toll subscriber connected thereto over a toll circuit, the overall Alength or characteristic of which exceeds' the signaling range ot the composite ringer at the trequency utilized. Accordingly, thereh ying device of this invention would be inserted at a desired intermediate point in this toll circuit and upon responding to signaling current sent out by the'central office, would transmit similar signalingcurrent toward the subscribers end oi' the toll circuit. with sufficient strength to operate apparatus thereat. The device ot the inventionaccordingly has been illustratedl as embodied in a toll circuit of' this type. However, it is understood that this is for purposes of illustration only, and that the relaying arrangements may be utilized in many other'types of circuits and with a number of different types ot signaling currents.

The invention may be more fully understood vtrom the following description together with the `accompanying drawing, in the Figures l and Q of which are shown circuit diagrams embodying a preferred form ot the invention and a modiiication thereof.

rThe arrangements ot' the invention as shown in Fig. l are embodied in a toll circuit comprising the line sections L and L1. The line section L will terminate in a jack J at a central oiiice, whereby it would be connected to a circuit which would transmit signaling current, such, for example,as QO-cycle eurrent, to the line section. The line section L1 would lead to a distantsubscribers station.

Let it be assumed that a QO-cycle signal is ap-y relay to operate. lts operation causes therelease oi' the relay 5, thereby completing the circuit from battery through the Winding olf relay 3 and ythe Contact of relay 5 to ground, as well as completing the circuit through relay l toground. Relay 3 is a 'faster operating relay than relay 1. As relay 3 operates it connects the ringing bridge involving relay 2 across the circuit and-opens the circuit between the source of signaling current and the ringing bridge involving relay 4. Relay 2 immediately responds to the incoming signal, and completes the circuit from battery through the winding of relay 3 to ground before this latter relay, which is oit the slowrelease type, has released. The operation of relay 2 also opens the circuit through the winding of relay l before relay l has oper- -i ated and prevents that relay'from operating. The release ot relay 4 has caused the operation of relay 5, and a circuit is now completed :trom battery through relay 6, contacts ot ielays 5 and 2, to ground. Relay 6, upon operating, disconnects the ringing bridge involving relay 4 from the circ-uit and applies QO-cycle signaling current towards the subscribers loop. lWhen the incoming signal ceases, relay 2 releases, causing the release of relays 3 and 6. Since relay 6 releases slightly before relay 3, a ring back towards the central otlice is prevented.

Assuming that a QO-cycle signal is being received over the line section L, from the subscribers loop, relay 4 will beoperated, causing the release of relay 5. The release oit' relay 5 causes the operation ot relay 3 and relay l. Relay l removes the ringing bridge, involving relay 2, from the circuit and applies QO-eycle signaling current over line section L to the central oiiice. Relay 3 operates slightly faster than relay l, thereby preventing a ring back. l/Vhen the incoming signal ceases, relay 4 releases, causing relay 5 to operate. Relays 3 and l then release, relay 1 releasing slightly faster than relay 3 thereby preventing a ring back.

In the modification illustrated in Fig. E2 similar parts, with respect to Fig. l, have been designated with the same reference characters, with the added designation of prime In the modilication shown in Fig. 2, two ringing bridges are employed rather than one ringing bridge as in Fig. 1. Let it be assumed that 20-cycle signaling current is applied to the relaying device from the switchboard through the jack J and over line section L. This signaling current will pass through both ringing bridges operating relay 2 and relay 4. The operation of relay 2 causes the cutoff relay 3 to operate. Relay 8 is a fast operating-slow release relay. The operation of relay 3 stops any further flow of the original 20-cycle signaling current through the windings of relay 4 and causes that relay to release. During the interval that relay 4 was operated, relay 5, which is a slow release-tast operating device, may have released. However, it was prevented from causing the operat-ion ot' relay 1, since the operation .of relay 2 opened the circuit between the armature of relay 5 and the winding of relay l. As soon as relay 5 returns to its normal operating condition the circuit t-hrough the winding of relay 6 to ground is completed through the contacts ot' relay 5 and relay 2. The operation of relay 6 removes vthe ringing bridge, consisting of relay 4 in series with a condenser, from the circuit and causes 20-cycle signaling current to be applied to line section L1 leading to the subscriber. Both relays 6 and 3 and 1 are of the slow-release type. However, relays l and 6 release slightly sooner than does relay 3, and this fact prevents the application of 20-cycle signaling ,current back over line .section L to the central oflice. l/Vhen the incoming signaling current ceases, relay 2 releases, thereby causing both relays 3 and 6 4to re'- lease.

Assume that a 20-,cycle signaling current is applied to the relaying arrangements from the subscribers set over line section L1. Signaling current will liow through the two ringing bridges, causing relays 4 and 2 to operate. The operation of relay 2 will complete the circuit through relay 3 to ground., causing it to operate. The operation ,of relay 4 will cause relay 5 to release, which also completes the circuit through the winding of relay 3 to ground, thereby keeping relay 3 in its operative position or bringing relay `3 to its operated position if relay 2 already responded to the signaling current. The release of relay 5 also opens the circuit between the winding of relay 6 and the ground which is on the cont-act of relay 2', thereby preventing the operation ot' relay 6. Relay 3 is a faster operating relay than relay (5. As soon as the cut-ott'- relay 3 operates, the signaling current iscut oil' from the ringing bridge involving relay 2 and that relay releases, completing the circuit from battery through the winding of relay 1, contacts of relay`s'2 and 5 to ground. Relay 1, upon operating, disconnects the ringing bridge involving relay 2 from the circuit, and 'also causes 20-cycle signaling current' to be applied over line Asection L to the central orifice. As the incoming signal ceases, relay 4 releases, causing relay 5 to operate,'which in turn causes the release of relays 3 land l.

While the invention has been disclosed as embodied in certain speciiic arrangements which are deemed desirable, it is to be understood that it is capable of embodiment in many other and widely varied forms without departing from the spiritoii the invention asdetined in the appended claim.

What is claimed is:

has not A tra-nsmission'line comprising ,two line sections interconnected over the contacts of a cutoff relay, a bridge vacross oneot said line sections including a signal responsive relay, means controlled by said signal responsive relay for operating said cut-oil' relay, a bridge .circuit adapted to be vconnected across the f Aother of said line sections by the operation of said lcut-off relay, signal responsive means in said bridge circuit,'n ieans" to complete a holding circuit for said cut-off relay directly over the Contact of said last mentioned signal responsive means, and means controlled said last mentioned signal responsive means for applying signaling current to said first mentioned line section.

In testimony whereof, we have signed our names to this specification this'19tfli day of November, 1926. y

SAMUEL P. SHACKLETON. ARNOLD A. HANSEN. 

